Tractor sprocket drive



Aug, 20, 1946.

J. EyLlLYL 2,406,230

TRACTOR sPRocxET DRIvE Filed sept. 4, 1944 3 Sheets-Sheet 1 Aug. 20,` 1946. J. E. LILL TRACTOR -sPRocKETDRI-VE Filed sept.' 4'. 1944 s sheets-sheet z Patented Aug. Z0, 1946 2,406,230 TRACTOR SPROCKET DRIVE .la-'nies E. Lili,v Los Angeles, Calif., assigner to Food llachinery Cor poration, San Jose, Calif.,

a corporation of Delaware Application september 4, 1944, serial Claims. (ol. isc-9.1)

This invention relates to power `transmissions and is particularly useful i' inl driving a drive sprocket inv a track laying vehicle-. n l I l Track laying mechanisms are employed on commercial tractors and military tanks and amphibians and each of these includes a exible endless track which is trained about front and rear drive and idle sprockets, and aseries of bogie wheels which ride on the lower flight of the track and thus supptitthe vehicle. i i

To increase the service performance characteristics 0i tractor type military vehicles the nach ing sprockets in the track` laying mechanisms thereof are placed forward to a point where these inevitably receive severe shocks due to the vehicle nosing into dirt embankments, rocks orl other obstacles in the effort to push these out of the way or ride over them. In certain vehicles it has been found advantageous to drive the track laying mechanisms from the leading' sprockets and a problem is here introduced of placing the drive sprockets far enough forward so that the tracks, where they pass around the drive sprockets, will engage and have traction on an embankment or other obstacle into which the vehicle is nosing.

It is an object of this invention to provide a mounting for a tractor drive sprt'ncket which may be mated ai; the from eric or the traer laying mechanism and which ne set in a sufficiently advanced position to prov1de traction on an obstacle as mentioned. l ,y u u It is another object of this invention toprovide a tractor sprocket drive emb'odyinga mount; ing for the sprocket which will employ the `Inlaterial used therein to especial advantage in withstanding shocksirom ramming against obstacles.

In a common type of tractor 'amphibian known as the Water Buffalo the sides offthe hull are provided with pontoons which lie within `the endless tracks of the track laying mechanisms. The rear ends of these pontoons are employed for mounting the idle sprockets of the track laying mechanisms. Heretofore, the drive sprockets of these amphibians have been mounted on bell housings extending laterally from the hull ahead of said pontoons.

It is another object of this invention to provide a tractor sprocket drive on which the drive sprockets in said Water Bulalo may be mounted and these sprockets driven "from, 'the front ends of said pontoons, thereby interposing a rigid compression structure between the v.front 'and rear sprocketsof eachv track laying mechanism which will greatly increase the capacity of thse track 'endless double chain track axis of the operational No. '552,684 v withstanding the shocks laying mechanisms to mentioned hereinabove.

The manner of accomplishing the foregoing cbjects as well as further objects and advantages will be made manifest in the following description taken in connection with the accompanying drawings in which:

Fig. 1 is a fragmentary diagrammatic plan View of an amphibian incorporating a preferred, embodment oi the track laying mechanism of my invention, and is partially broken away substantially as indicated by line I-I of Fig. 2 to reveal the internal construction of said amphibian.

Fig. 2 is a side elevational view Vof Fig. 1.

Fig. 3 is a vertical sectional view of the tracn tor sprocket drive of my invention taken on the line 3 3 of Fig. l.

Fig. 4 is a horizontal sectional View on stepped levels as indicated by the line 4-4 in Fig.

Al'ig. 5 is a perspective vien/'showing the main gear housing of the invention. a Referring specically to the drawings the invention is disclosedas incopcrated with an amphibian il! comprising a hlll l having sides l2, arcurved bow i3, a bttoin ini and a stern plate 1 5. Provided in the hull H is a pilcts compartmeetic Assembled upon the sides L2 to extend outward lytherefrom are ponto'ons 2B each of which has a front wall 2l, top wall 22, a bottom wall 23, a rear wall 24 and an outside wall 25. Mounted on each of the pntoons 2D is a Vtrack laying land-traction and water-pro ulsion mechanism 3B which includes aseries of bog'ie wheels 3i which are rotatably supported in any prefered manner on the pontoon ,bottom 23. Each such mechanism also includes a double idle sprocket 32, and

a double drive sprocket A33, these sprockets being I the hull Il, and an 3d whichV is` trained and the bogie wheels located at opposite ends of about the sprockets 32 and 33 3| The double idle "sprocket 32 is rotatable on a b'ase B which is slideably mounted on the rear end ofthe pontoon V2l) `(see Fig. 2) and is shiftable horizontally by a jack "40 to loosen or tighten the endless track 34.

The `double drive sprocket 33 of this invention is mounted on the frcnt end of the pontoon 2r] so as to provide a continuous compression member which lies along and on opposite sides of the i I l i compressive vforces applied by the track 34 to the two double sprockets 32 and 33,7tending toiorce one vvof these towards the other. Such compressive forces include strains Vand 46 are united integrally holes 48 and49.

Vmeshing with the gear wheel 18.

- and drive rods off unit 62.

caused by the caused by head on collisions with obstacles in the path of the amphibian l0. l

To eifect this purpose, my invention preferably includes a drive sprocket mounting and driving device 4| which is mounted on the front pontoon wall 2|. These devices are reverse duplicates of each other so that a description of the left device which follows will suiiice for both. Y The left device 4| includes a main housing casting 42 having an attachment flange 43 Yby which the casting 42 Yis secured to the front pon-` toon wall 2| as by bolts or rivets. The housing 42 has a top wall 44 anda bottom wall 45 extending forwardly from the flange 43` and uniting with a curved front wall 46. The walls 44, 45 by side walls 41 which are provided with pairs of axially disposed 42 also includes a compartment 56 extending rearwardly from the perimetric flange 43'a'nd having an upper wall 6|, a bottom wall 52 and a rear wall 53 which are connected by side walls 54, the latter having coaxial openings 55 therein.

The rearrwall 53 is provided with an opening 56. This opening is adapted to receive a neck 69 of a'box 6| of a power take-off unit 62. VThe invention is adapted to be employed with or without the unit s2y and when this unit is dispensed with the opening 56 is covered with a suitable plate.

The double drive sprocketl 33, which the device 4| is provided for mounting and driving, comprises individual sprockets 65 having splined hub sleeves 66 which extend into and mesh with an internally splined hub 61 of a gear 68. The sprockets 65 are held in assembly with the hub 61 by a bolt 66 which also traps bearings 16 be- The housing tween the hub 61 and the sprockets 65.

Secured to the side walls 41 of the housing 42 so as to close the openings 48 therein and rigidlyV position the. assembled sprocket 65, gear wheel 68 and bearing 16, are cover plates 15.1

Secured in the openings idle shaft 11 on which is provided a bearing 18 mounting a countergear wheel 19, the latter Y Fixed to the outer side wall 54 andr extending into` its opening 55 is a bearing support cap -60 in which a bearing 8| rests. Fixed to the inner side wall 54 so as to extend into the inner opening 55 is a cap S which houses bearings' and 81.

Rotatably mounted in the bearings 3| and 86 is a sleeve 88 having a pinion gear 89 formed thereon as well as a bevel gear 90. kThe pinion gear 68 meshes with the countergear wheel 19. The interior of the sleeve 83 is splined and a differential drive shaft 9| which is internally splined extends into the sleeve 88 in splined driving relation therewith. The shaft 9| also journals in the bearing 81. A suitable packing ring 92 is provided in the cap 85 about the shaft 9 y The shafts 9| of the two mounting and driving devices 4| connect through universal joints 93 94 and 95 with a selective gear transmission 96 to which power is delivered through a drive shaft `91 from an internal combustion motor (not shown).

VThe mechanism already described in detail may be employed, for mounting and driving the double drive sprockets 33 without the power `take- Y This unit 62 is employed whenever it is desired to supply power within the pontoons concurrently with the driving lof thetrack 49 by plates 16 isan driving of the track or shocks laying mechanisms of the amphibian I0. One such instance is where propellers are mounted in these pontoons in the manner and for the pur= pose disclosed in the co-pending application ci James M. Halt, Serial No. 554,989, led September 20, 1944.

The box 6| of the power take-off unit 62 supports bearings |02 and |33 in which is journaled a shaft |04 carrying a bearing |65 on whicha clutch gear |65 is freely rotatable. Splined on the shaft |54 is a clutch collar |61 which is shiftable by a yoke |08 into and out of clutching engagement with the gear |66. The yoke |68 is fixed on a slide shaft |69 mounted in the box 6| and shiftable by a manually controlled lever H6.

Fixed on the inner end of the shaft |04 so as to mesh with the bevel gear 96 is a bevel pinion H5. The box 6| also provides bearings ||6 and |i1 for a power take-olf shaft ||8 having a pinion ||9 which meshes with the gear |06.

Each device 4| may be lubricated by the splash system, To effect this and for .inspection purposes, the housing 42 is provided with an oil baffle |20 and with plugged ports |2| and |22 through which oil may be introduced and the mechanism inspected when desired.

Operation sists head-on shocks imposed on the drive sprocket with forces which are disposed symmetrically with respect to the axis along which the shocks are imposed. It is evident that for the amount of material employed in the drive sprocket support4l, this is very much stronger and more able thefbe'll housing sprockto resist such shocks than et supports in previous use inabove.

In operating the amphibian I the pilot utilizes the transmission `|l6 to selectively drive the port and starboard track laying mechanisms 36. Each of these mechanisms are driven, of course, by rotation of its shaft 9| nection withI the pinion so that the latter rotates with this shaft. Through this pinions meshing with gear 18, and the latter meshing with gear 68, the sprocket 33 is rotated.

When lthe devices 4| are employed on amphibians it is, of course, desirable that these be as light as possible while, at the same time, have the necessarystrength. For this reason I prefer to cast the housing from steel. The cover plates 15, the bearing support caps 8|! .and 85 and the power takeoif box 6|, I find may advantageously be made of a suitable aluminum alloy.

When the devices 4| have power take-off units 62 associated therewith, as shown in theV drawings, power may be transmitted from the takeoii shafts ||8 through drive rods |25 to whatever mechanisms require driving.

The claims are as follows:

1. In a tractor type vehicle, of: a double tractor drive sprocket having spaced individual sprockets `connected axially by hub means; spaced bearings surrounding said hub means between said individual sprockets; a housing extending between said individual sprockets and providing-a mounting for said bearings; means disposed radially outside the periphery of said double sprocket for rigidly supporting said and referred to herewhich has a splined con- Y 42 of each of these devices the combination f and operatively connected to said hub means for rotating said double sprocket.

2. In a tractor type vehicle, the combination of a double drive sprocket including spaced individual sprockets connected by a hub; a double idle sprocket comprising spaced individual sprockets connected by a hub; a flexible endless track trained about said double sprockets; bearing means for said hubs; a compression structure disposed between said drive sprocket and said idle sprocket and lying on opposite sides of the plane bisecting the space between said individual sprockets;.means on said compression structure extending between said individual sprockets of each of said double sprockets and rigidly supporting the bearing means thereof on said compression structure; and means extending from said compression structure into the space between the bearings of said double drive sprocket for rotating the latter.

3. In a tractor type vehicle the combination the periphery of said sprocket for rigidly supportsaid axle means between said bearings for rotating said double drive sprocket.

4. A combination as in claim 3 in which said axle rotating means includes a gear mounted on said axle means between said bearings.

5. A combination as in claim 3 in which said drive means comprises a train of gears, one of which is mounted on said axle means between said bearings.

JAMES E. LILL. 

